Many packaging applications use resealable containers to store various types of articles and materials. These packages may be used to store and ship food products, non-food consumer goods, medical supplies, waste materials, and many other articles.
Resealable packages are convenient in that they can be closed and resealed after the initial opening to preserve the enclosed contents. The need to locate a storage container for the unused portion of the products in the package is thus avoided. As such, providing products in resealable packages appreciably enhances the marketability of those products.
The resealable closure mechanism is often produced as a separate item from the package and is attached to and made integral with the package at a later point in the manufacturing process. Each separate closure profile includes a base strip and interlocking member.
One closure profile may have a rib or male member and the other, a mating groove or female member. The male or female member extends from the front face of the base strip. The rib and groove form a pressure fastenable and releasable closure mechanism. The back side, or sometimes an extended portion of the front face of the base strip is sealed to the package film so this closure mechanism is disposed between the package walls adjacent to the openable side of the package.
One disadvantage of this closure arrangement is that the side seals often are not leak-proof. When the sides of the package are sealed, the sealing process leaves a gap above or below the closure mechanism due to the larger thickness of the closure profiles relative to the package films. This gap allows materials, and in particular fluids, to leak out the side of the package.